for you master cyl. brake bleed folks who have experienc....
 

put in new metelli master cylinder
all new brake hoses
rebuilt both rear calipers, fronts are recent

bench bled the master poorly, didn't have right technique
bench bled it again after installed in the car
got only a few blobs of air in the first several rounds of plungeing the cylinder

then zero more air

still with the mushy deep diving pedal

84 300TD

anybody know what I'm doing wrong??

Check your PM.

Sixto
83 300SD

Thx for that

I've got a syringe here and have adapted it to funtion like that cardone tool

from the video they produced it looks to me like it makes a lot of sense

those bubbles want to to up, no other direction

I'l get more brake fluid and take the thing out and run the bench bleed, or maybe do it still installed

I'll post the result

I had one on the SD that was a real pita to bleed. The final solution was a pressure bleeder. The pedal still seemed soft with the car up on stands but it was perfect with the car on the ground.

I now get a cap and make a car specific bleeder connection the 1st time I have to bleed a new car. The caps are stored in an old coffee can in the shop and are even easy to find when needed because they are messy when stored any place else.

Kent on youtube , said important not to get any air in the ABS brake system as its hard to remove it after .But can be done by pressure bleeding them .

I omitted these facts in the original post, but added them in just now, in, this is 84 300TD, no ABS

Also added my bleeding technique which is pressure , 15 or 20 psi in reservoir, its my only way for this vehicle, I agree its quite convenient especially since it does not require another person on hand to help.

Thx

I just went thru putting a master on my 85 with ABS. I first tried to just bleed them with home made pressure bleeder at 20 psi. and made the mistake of running dry and got more air in system the brakes got no better. I got a new master cyl. brench bled the cyl. with a kit you can get for about $5 but I had to get 2 kits as the kit only came with 1 correct mm fitting for the port connections and I needed 2 and the kit came with black non see thru hoses which I got new see thru hoses so I could better see how much and when air was bled. Took pretty many pumps to get all the air out and I dont think its good to go all the way on the pump I would stop a little before end of travel. Ounce bled put it on be careful you get brake lines started straight bleed it with pressure bleeder and now I have great brakes again.

The most often overlooked problem with bleeding these brakes is a simple one. There is a separate chamber in the fluid reservoir for the rear brakes, and the divider between the chambers is very high. To get fluid into the rear portion you need to pour it in all the way up to the neck of the reservoir.

Sounds right. I do keep it high, lately, usually to the brim. Crazy too much time in mental goof state with something not complex .... seeming to not make sense.

FWIW, I had a hell of a time bleeding a parts store MC. I installed a known good OE booster and MC and got it working nicely. Maybe there was still fluid in the MC but it had been on a shelf for years and I dry pumped it many times before filling with fresh fluid.

Sixto
83 300SD

for the master cyl. bleeding im sold on the retrograde method

using a large piston syringe, 1 in. diameter, 6 in. .long, push new brakefluid from output opening into the cylinder and then on up to fill the reservoir.

Big burps of air come out instantly .... it (air) wants to to up anyway.

Cant have any air in that fluid

OK here we go. Too the brim. No bs.

Correct that you can "bench" bleed w/ MC installed in the car. I always do so. Might take 50 strokes to sweep all the air bubbles thru to see solid liquid. Many youtube videos.

Replaced many euro car MC's and I've never bench bled. Install new MC, fill reservoir, attach Motive pressure bleeder with 2 liters of fluid in it, and go from one caliper to the next until there's no bubbles coming out. Go in order from furthest to closest i.e. RR, LR, RF, LF. Results in a high firm pedal every time.

I believe it. Seem the problem here is a new MC that is junk strait out if the box.

Thx

x2. I recently wrestled with a McParts store MC I couldn't bleed. I have a Motive pressure bleeder you're welcome to try but I think it needs a new hose.

Sixto
83 300SD
98 E320 wagon